Crosslinkable rubber compositions and uses thereof

ABSTRACT

The crosslinkable rubber composition is crosslinkable at room temperature, has a gelation time at room temperature of 30 days or less, and can prepare a crosslinked rubber sheet by crosslinking the composition at room temperature, wherein the crosslinked rubber sheet has a tensile elongation of 20% or more, and is free of cracks after treatment at 40° C. in a 50 pphm ozone concentration for 96 hr. Specifically, it comprises an ethylene/α-olefin/non-conjugated polyene random copolymer rubber comprising a norbornene compound having a specific vinyl end group, an SiH group-containing compound, which has at least two SiH groups in one molecule, and optionally a platinum catalyst, a reaction inhibitor and/or a silane-coupling agent. The sealing, potting and coating materials and adhesives of the present invention comprise the above rubber composition.  
     The rubber composition has a high crosslinking rate at room temperature and excellent productivity, and can prepare crosslinked rubber molded products (including foamed products) having excellent weathering resistance, ozone resistance, heat aging resistance and compression set at low cost. Further, it is suitable for use of electric and electronic parts, transportation machines, civil engineering and construction materials, medical appliances and goods for leisure activities.

FIELD OF THE INVENTION

[0001] The present invention relates to rubber compositionscrosslinkable at room temperature and uses thereof. More particularly,the present invention relates to crosslinkable rubber compositions whichenable high crosslinking rate at room temperature, efficientproductivity to produce a crosslinked rubber molded product, andlow-cost production of a crosslinked rubber molded product excellent inweather, ozone, heat aging and compression set resistances, and the usesthereof. The invention also relates to crosslinkable rubber compositionshaving excellent moldability and adhesion in addition to the aboveproperties, which are thus suitable as a sealing material and the like,and uses of the compositions.

BACKGROUND OF THE INVENTION

[0002] Curing materials have been employed in sealing, coating, pottingand bonding of items in industries involving electric and electronicparts or transport aircrafts, and in other industries, such as civilengineering and construction, medical and leisure industries.

[0003] An exemplary curing material is one (composition) comprising anorganic polymer having a silicon-containing group which contains ahydroxyl group or a hydrolyzable group each bonded to a silicon atom andis crosslinkable by formation of a siloxane bond.

[0004] The curing material requires moisture at its curing and thecuring takes a long time.

[0005] In order to solve the above problems, a composition has beendeveloped wherein polyorganosiloxane having at least two vinyl groups onthe average in one molecule is crosslinked with anorganohydrogensiloxane having 2 or more hydrogen atoms bonded to asilicon atom in a molecule. The composition can be employed as thecuring material for its excellent weather, water and heat resistances.However, the composition has defects such as high costs, poor adhesion,easy outbreak of fungus and unsatisfactory resistance to gaspermeability, which limits therefore its applications.

[0006] A composition disclosed in Japanese Patent Application Laid-OpenNo.4(1992)-185687 solves the above problem. This composition comprises acompound having at least one alkenyl group in a molecule, a compoundhaving at least two hydrosilyl groups in a molecule, a hydrosilylationcatalyst, and a silane coupling agent. In the examples described in thispublication, use was made of terminal-allyl group etherifiedpolyoxypropylene, polypropyleneoxide having a hydrosilyl group,allyl-terminated polycaprolactam, polycaprolactam having cyclichydrogenpolysiloxane, allyl-terminated polyisoprene, and hydrogenatedpolyisoprene having cyclic hydrogenpolysiloxane.

[0007] According to the present inventors' supplementary examination forthe examples of the publication, admittedly shorten curing time andimproved adhesion, but the curing rate, the weather resistance and theheat aging resistance remained unsatisfying. The adhesion still requiredfurther improvement.

[0008] The present inventors therefore made an earnest study on anethylene/α-olefin/non-conjugated polyene random copolymer rubbercomposition, and found that a rubber composition comprising anethylene/α-olefin/non-conjugated polyene random copolymer rubber (A), anSiH group-containing compound (B) containing at least two SiH groups inone molecule, and optionally, a catalyst (C), a reaction inhibitor (D) ,a silane coupling agent (E) and a plasticizer (F) enables highcrosslinking rate at room temperature, efficient productivity to producea crosslinked rubber molded product, and low-cost production of acrosslinked rubber molded product excellent in weather, ozone, heataging and compression set resistances. Based on such findings, thepresent invention has been completed.

OBJECT OF THE INVENTION

[0009] The present invention has been made to solve the problemsassociated to the prior art, and an object of the present invention isto provide crosslinkable rubber compositions which enable highcrosslinking rate at room temperature, efficient productivity to producea crosslinked rubber molded product, and low-cost production of acrosslinked rubber molded product which is excellent in weather, ozone,heat aging and compression set resistances, and is attractive in termsof production costs. It is another object of the present invention toprovide crosslinkable rubber compositions having excellent moldabilityand adhesion in addition to the above properties, which are thussuitable as a sealing material or the like. It is further object of thepresent invention to provide products which comprise the compositions,and are excellent in curing rate, weather resistance, heat agingresistance and adhesion, particularly with inorganic materials such as ametal, which products are clarified by sealing, potting and coatingmaterials and an adhesive employed in industries involving electric andelectronic parts or transportation machines, and in other industries,such as civil engineering and construction, medical and leisureindustries.

SUMMARY OF THE INVENTION

[0010] The first crosslinkable rubber composition of the presentinvention is crosslinkable at room temperature (25° C.) ,has a gelationtime at room temperature of 30 days or less, and has properties that acrosslinked rubber sheet obtained by crosslinking the composition atroom temperature has a tensile elongation of 20% or more (JIS K-6251:measurement temperature 20° C.; tensile rate 500 mm/min) and has nocrack after a treatment at 40° C. in a 50 pphm ozone concentration for96 hr in accordance with an ozone deterioration test method defined inJIS K-5259.

[0011] The gelation time is determined as follows. The change infrequency was measured using a scanning VNC (SVNC) (manufactured byRapra Technology Ltd.). The frequency increases with proceeding of thismeasurement, and when it stabilized, it was taken to be 100%. The timethat the frequency changed 95% was taken as the gelation time(crosslinking time). The measuring temperature was room temperature andthe measuring procedure was carried out according to the followingliteratures.

[0012] (i) RAPRA Operation manual (Software Ver. 2.2) of Scanningvibrating needle type curemeter (scanning VNC)

[0013] (ii) RAPRA Curing comprehension (RTL/2844) Scanning vibratingneedle type curemeter (scanning VNC).

[0014] The second crosslinkable rubber composition according to thepresent invention comprises:

[0015] (A) an ethylene/α-olefin/non-conjugated polyene random copolymerrubber having structural units derived from at least one norbornenecompound having a vinyl group at the end, which is non-conjugatedpolyene, represented by the formula (I) or (II),

[0016]  wherein n is an integer of 0 to 10,

[0017] R¹ is hydrogen or an alkyl group of 1 to 10 carbon atoms, and

[0018] R² is hydrogen or an alkyl group of 1 to 5 carbon atoms;

[0019]  wherein R³ is hydrogen or an alkyl group of 1 to 10 carbonatoms, and

[0020] (B) an SiH group-containing compound having at least two SiHgroups in one molecule; and has

[0021] a gelation time at room temperature (25° C.) of 30 days or less.

[0022] The second crosslinkable rubber composition according to thepresent invention may comprise:

[0023] (A) an ethylene/α-olefin/non-conjugated polyene random copolymerrubber,

[0024] (B) an SiH group-containing compound having at least two SiHgroups in one molecule, and

[0025] (C) a catalyst,

[0026] or it may comprise:

[0027] (A) an ethylene/α-olefin/non-conjugated polyene random copolymerrubber,

[0028] (B) an SiH group-containing compound having at least two SiHgroups in one molecule,

[0029] (C) a catalyst, and

[0030] (D) a reaction inhibitor and/or

[0031] (E) a silane coupling agent.

[0032] The second crosslinkable rubber composition may further comprisea plasticizer (F) in an amount of 1 to 1,000 parts by weight based on100 parts by weight of the ethylene/α-olefin/non-conjugated polyenerandom copolymer rubber (A). The above amount of plasticizer (F) ispreferable when the ethylene/α-olefin/non-conjugated polyene randomcopolymer rubber (A) has the following properties (i) to (v).

[0033] The ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) has:

[0034] (i) a molar ratio of ethylene to an α-olefin of 3 to 20 carbonatoms (ethylene/α-olefin) of 40/60 to 95/5,

[0035] (ii) an iodine value of 0.5 to 50, and

[0036] (iii) an intrinsic viscosity (η) as measured in decalin at 135°C. of 0.01 to 2 dl/g.

[0037] In addition to the properties (i) , (ii) and (iii) the copolymerrubber (A) preferably has:

[0038] (iv) a molecular weight distribution (Mw/Mn) determined by GPC of3 to 100, and

[0039] (v) an effective network chain density (v), as measured after theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A) ispress crosslinked at 170° C. for 10 min using 0.01 mol ofdicumylperoxide based on 100 g of the copolymer rubber (A), of 0.5×10²⁰chains/cm or more.

[0040] In addition to the properties (i), (ii), (iii), (iv) and (v), theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A)more preferably has:

[0041] (vi) a relation between a ratio of a shear rate γ₂ correspondingto a shear stress of 2.4×10⁶ dyn/cm² to a shear rate γ₁ corresponding toa shear stress of 0.4×10⁶ dyn/cm² (γ₂/γ₁), both obtained by a melt flowcurve at 100° C., and the effective network chain density (ν) satisfiesthe formula (III):

0.04×10⁻¹⁹≦Log(γ₂/γ₁)/ν≦0.20×10⁻¹⁹  (III).

[0042] The ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) having the properties (i) to (vi) can be produced, forexample, by copolymerization of ethylene, an α-olefin and a norbornenecompound of the formula (I) or (II) using a catalyst containing thefollowing compounds (H) and (I) as main components under the conditionsof a polymerization temperature of 30 to 60° C., a polymerizationpressure of 4 to 12 kgf/cm², and a feed rate molar ratio (non-conjugatedpolyene/ethylene) of the non-conjugated polyene to ethylene of 0.01 to0.2.

[0043] (H) A soluble vanadium compound represented by the formula:VO(OR)_(n)X_(3−n), wherein R is a hydrocarbon group, X is a halogenatom, and n is 0 or an integer of 1 to 3, or a vanadium compoundrepresented by the formula: VX₄ wherein X is a halogen atom.

[0044] (I) An organoaluminum compound represented by the formula:R′_(m)AlX′_(3−m) wherein R′ is a hydrocarbon group, X′ is a halogenatom, and m is 1 to 3.

[0045] The ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) preferably has an insoluble content of 1% or less aftersubjecting to Soxhlet extraction (solvent: boiling xylene, extractiontime: 3 hr, mesh: 325).

[0046] As the catalyst (C), a platinum catalyst is preferably employed.

[0047] Preferably, the second crosslinkable rubber composition of thepresent invention is crosslinkable at room temperature, has a gelationtime at room temperature of 30 days or less, and has properties that acrosslinked rubber sheet obtained by crosslinking the composition atroom temperature has a tensile elongation of 20% or more (JIS K-6251:measurement temperature 20° C.; tensile rate 500 mm/min) and has nocrack after a treatment at 40° C. in a 50 pphm ozone concentration for96 hr, and particularly,

[0048] a crosslinking rate (t_(c)(90)) at 160° C. of 15 min or less.

[0049] The first and the second crosslinkable rubber compositionspreferably have an adhesion strength to aluminum (JIS A5758(1986)) of0.1 to 20 MPa, preferably 0.2 to 15 MPa, more preferably 0.5 to 10 MPa,particularly preferably 1 to 5 MPa.

[0050] The third crosslinkable rubber composition of the presentinvention comprises the ethylene/α-olefin/non-conjugated polyene randomcopolymer rubber (A) and the SiH group-containing compound (B), and hasan adhesion strength (JIS A5758 (1986)) to aluminum of 0.1 to 20 MPa.

[0051] The fourth crosslinkable rubber composition of the presentinvention comprises the ethylene/α-olefin/non-conjugated polyene randomcopolymer rubber (A) and the SiH group-containing compound (B), whereinthe copolymer rubber (A) has an intrinsic viscosity (η) as measured indecalin at 135° C. of 0.01 to 0.95 dl/g.

[0052] The third crosslinkable rubber composition of the presentinvention may be the fourth crosslinkable rubber composition.

[0053] The third and the fourth crosslinkable rubber compositions mayoptionally contain a catalyst (C), a reaction inhibitor (D), a silanecoupling agent (E), and a plasticizer (F) within the limit notdetrimental to the object of the present invention.

[0054] The first to the fourth crosslinkable rubber compositions of theinvention are preferably used for electric and electronic parts,transportation machines, civil engineering and construction materials,medical appliances and leisure activity goods.

[0055] Uses for the electric and electronic parts include sealingmaterials, potting materials and coating material and adhesivesrespectively applied to heavy electric apparatus parts, light electricalappliance parts, or circuits and substrates of electric and electronicmachinery and tools; repairing materials for covered electric wire;insulating sealing materials for electric wire joint parts; rolls foroffice automation equipments; vibration absorbing materials; and gels orencapsulation materials for condensers.

[0056] The sealing materials are suitably used for refrigerators,freezers, washing machines, gas meters, microwave ovens, steam irons andcircuit breakers.

[0057] The potting materials are suitably used for potting transformerhigh-tension circuits, printed boards, high voltage transformersequipped with a variable resistor, electrical insulating parts,semi-conductive parts, conductive parts, solar cells, and TV fly-backtransformers.

[0058] The coating materials are suitably used for coating circuitelements such as a high voltage thick film resistor and a hybrid IC;HIC; electrical insulating parts; semi-conductive parts; conductiveparts; modules; printed circuits; ceramic boards; buffer materials fordiodes, transistors and bonding wires; semi-conductive elements; andoptical fibers for optical communication.

[0059] The adhesives are suitably used for bonding cathode-ray tubewedges or necks, electrical insulating parts, semi-conductive parts andconductive parts.

[0060] The transportation machines are automobiles, ships, airplanes andrailway vehicles.

[0061] Uses for the automobiles include sealing materials for gaskets ofautomobile engines, electric trim parts and oil filters; pottingmaterials for ignitor HIC and automobile hybrid IC; coating materialsfor automobile bodies, automobile window glass and engine controlsubstrates; and adhesives for gaskets of oil pans, gaskets of timingbelt covers, other automotive gaskets, automotive moles, head lamplenses, sun roof seals and mirrors.

[0062] Uses for the ships include sealing materials for wiring andconnecting distributor boxes, electric system parts and electric wires;and adhesives for electric wires and glass.

[0063] Uses for the civil engineering and construction include sealantsof building material for butt joints in glass screen method ofcommercial buildings, joints of glass fringes fixed with sash, interiorfinishing joins of toilet facilities, lavatory and show cases, joints ofbath tub circumferences, outer wall expansion joints of prefabricationhouses, and joints of siding boards; sealing materials for doubleglazing units; civil engineering sealants used in road maintenance;coatings and adhesives for metals, glass, stone materials, slates,concretes and tiles; and adhesive sheets, water proofing sheets andvibration-proof sheets.

[0064] Uses for the medical appliances include sealing materials formedicinal rubber stoppers, syringe gaskets and rubber stoppers forreducing blood pressure.

[0065] Uses for the goods for leisure activities include swimmingmaterials, such as swimming caps, diving masks and earplugs; and gelbuffer materials for sport shoes and baseball gloves.

[0066] The sealing, potting and coating materials and the adhesivesaccording to the present invention comprise any one of the first to thefourth crosslinkable rubber compositions of the invention.

BEST MODE TO CARRY OUT THE INVENTION

[0067] The crosslinkable rubber compositions and uses thereof of thepresent invention are described below in more detail.

[0068] The first crosslinkable rubber composition of the presentinvention is crosslinkable at room temperature (25° C.) , has a gelationtime at room temperature of 30 days or less, and has properties that acrosslinked rubber sheet obtained by crosslinking the composition atroom temperature has a tensile elongation of 20% or more (JIS K-6251:measurement temperature 20° C.; tensile rate 500 mm/min) and has nocrack after a treatment at 40° C. in a 50 pphm ozone concentration for96 hr in accordance with an ozone deterioration test method defined inJIS K-5259.

[0069] The second crosslinkable rubber composition of the inventioncomprises an ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) , an SiH group-containing compound (B) containing at leasttwo SiH groups in one molecule, and optionally a catalyst (C), areaction inhibitor (D) a silane coupling agent (E), and a plasticizer(F), and has a gelation time at room temperature of 30 days or less.

[0070] The second crosslinkable rubber composition of the presentinvention is preferably crosslinkable at room temperature (25° C.), hasa gelation time at room temperature of 30 days or less, and hasproperties that a crosslinked rubber sheet obtained by crosslinking thecomposition at room temperature has a tensile elongation of 20% or more(JIS K-6251: measurement temperature 20° C.; tensile rate 500 mm/min)and has no crack after a treatment at 40° C. in a 50 pphm ozoneconcentration for 96 hr, which rubber has the same properties as thefirst rubber composition of the present invention.

[0071] These rubber compositions have a gelation time at roomtemperature of 30 days or less, preferably 20 days or less, morepreferably 10 days or less, even more preferably 7 days or less, stillpreferably 5 days or less, highly preferably 3 days or less,particularly preferably 2 days or less, most preferably 1 day or less.

Ethylene/α-olefin/non-conjugated polyene random copolymer rubber (A)

[0072] The ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) for use in the invention is a random copolymer of ethylene,an α-olefin of 3 to 20 carbon atoms and non-conjugated polyene.

[0073] Examples of the α-olefin of 3 to 20 carbon atoms includepropylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene,1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene,1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicosene,9-methyl-1-decene, 11-methyl-1-dodecene and 12-ethyl-1-tetradecene.Among these, preferable are α-olefins of 3 to 10 carbon atoms, andparticularly preferable are propylene, 1-butene, 1-hexene and 1-octene.

[0074] These α-olefins are used singly or in combination of two or morekinds.

[0075] The non-conjugated polyene for use in the invention is anorbornene compound having a vinyl group at the end represented by thefollowing formula (I) or (II):

[0076] In the formula (I), n is an integer of 0 to 10,

[0077] R¹ is hydrogen or an alkyl group of 1 to 10 carbon atoms,specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl,sec-butyl, t-butyl, n-pentyl, isopentyl, t-pentyl, neopentyl, hexyl,isohexyl, heptyl, octyl, nonyl and decyl groups; and

[0078] R² is hydrogen or an alkyl group of 1 to 5 carbon atoms.

[0079] Examples of alkyl groups of 1 to 5 carbon atoms for R² includethose of 1 to 5 carbon atoms exemplified with respect to R¹.

[0080] In the formula (II), R³ is hydrogen or an alkyl group of 1 to 10carbon atoms.

[0081] Examples of alkyl groups for R³ include the same ones asexemplified with respect to R¹.

[0082] Examples of the norbornene compound represented by the formula(I) or (II) include:

[0083] 5-methylene-2-norbornene, 5-vinyl-2-norbornene,

[0084] 5-(2-propenyl)-2-norbornene,

[0085] 5-(3-butenyl)-2-norbornene,

[0086] 5-(1-methyl-2-propenyl)-2-norbornene,

[0087] 5-(4-pentenyl)-2-norbornene,

[0088] 5-(1-methyl-3-butenyl)-2-norbornene,

[0089] 5-(5-hexenyl)-2-norbornene,

[0090] 5-(1-methyl-4-pentenyl)-2-norbornene,

[0091] 5-(2,3-dimethyl-3-butenyl)-2-norbornene,

[0092] 5-(2-ethyl-3-butenyl)-2-norbornene,

[0093] 5-(6-heptenyl)-2-norbornene,

[0094] 5-(3-methyl-5-hexenyl)-2-norbornene,

[0095] 5-(3,4-dimethyl-4-pentenyl)-2-norbornene,

[0096] 5-(3-ethyl-4-pentenyl)-2-norbornene,

[0097] 5-(7-octenyl)-2-norbornene,

[0098] 5-(2-methyl-6-heptenyl)-2-norbornene,

[0099] 5-(1,2-dimethyl-5-hexenyl)-2-norbornene,

[0100] 5-(5-ethyl-5-hexenyl)-2-norbornene and

[0101] 5-(1,2,3-trimethyl-4-pentenyl)-2-norbornene. Among these,preferable are 5-vinyl-2-norbornene,

[0102] 5-methylene-2-norbornene,

[0103] 5-(2-propenyl)-2-norbornene,

[0104] 5-(3-butenyl)-2-norbornene,

[0105] 5-(4-pentenyl)-2-norbornene,

[0106] 5-(5-hexenyl)-2-norbornene,

[0107] 5-(6-heptenyl)-2-norbornene and

[0108] 5-(7-octenyl)-2-norbornene. These norbornene compounds can beused singly or in combination.

[0109] With the norbornene compound such as 5-vinyl-2-norbornene,non-conjugated polyene can be used in combination within limits notdetrimental to the aimed properties of the invention.

[0110] Examples of the non-conjugated polyene are:

[0111] chain non-conjugated dienes, such as 1,4-hexadiene,3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene,4,5-dimethyl-1,4-hexadiene, and 7-methyl-1,6-octadiene;

[0112] cyclic non-conjugated dienes, such as methyltetrahydroindene,5-ethylidene-2-norbornene, 5-methylene-2-norbornene,5-isopropylidene-2-norbornene, 5-vinylidene-2-norbornene,6-chloromethyl-5-isopropenyl-2-norbornene and dicyclopentadiene; and

[0113] trienes, such as 2,3-diisopropylidene-5-norbornene,2-ethylidene-3-isopropylidene-5-norbornene, and2-propenyl-2,2-norbornadiene.

[0114] The ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) comprising the above components has the following properties.

[0115] (i) Molar Ratio of Ethylene to an α-Olefin of 3 to 20 CarbonAtoms (Ethylene/α-Olefin)

[0116] The ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) contains constituent units (a) derived from ethylene andconstituent units (b) derived from an α-olefin of 3 to 20 carbon atoms(sometimes referred to simply as “α-olefin” hereinafter) in a molarratio ((a)/(b)) of 40/60 to 95/5, preferably 50/50 to 90/10, morepreferably 55/45 to 85/15, particularly preferably 60/40 to 80/20.

[0117] When the molar ratio is in the above range, there can be obtaineda rubber composition capable of providing a crosslinked rubber moldedproduct excellent in low-temperature resistance and processability aswell as in heat aging resistance, strength properties and rubberelasticity.

[0118] (ii) Iodine Value

[0119] The ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) has an iodine value of 0.5 to 50 (g/100 g), preferably 0.8 to40 (g/100 g), more preferably 1 to 30 (g/100 g), highly preferably 1.5to 25 (g/100 g).

[0120] When the iodine value is in the above range, there can beobtained a rubber composition having a high crosslinking rate at roomtemperature, and a crosslinked rubber molded product excellent incompression set resistance and in environmental deterioration resistance(i.e., heat aging resistance). An iodine value exceeding 50 is notfavorable because of disadvantageous costs.

[0121] (iii) Intrinsic Viscosity

[0122] The intrinsic viscosity (η) of theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A) ,as measured in decalin at 135° C., is in the range of 0.01 to 2 dl/g,preferably 0.02 to 1.8 dl/g, more preferably 0.05 to 1.5 dl/g, highlypreferably 0.1 to 1.4 dl/g. When the intrinsic viscosity (η) is in theabove range, there can be obtained a rubber composition which hasexcellent flowability, and is capable of providing a crosslinked rubbermolded product having excellent strength properties and compression setresistance.

[0123] The intrinsic viscosity (η) is desired to be in the range of 0.01to 0.95 dl/g, preferably 0.05 to 0.90 dl/g, more preferably 0.1 to 0.8dl/g, highly preferably 0.3 to 0.7 dl/g, from the viewpoints of themoldability, adhesion, and post-bonding strength.

[0124] Further, the intrinsic viscosity (η) is desired to be in therange of 0.01 to 0.5 dl/g, preferably 0.01 to below 0.3 dl/g, morepreferably 0.1 to 0.25 dl/g, from the viewpoints of the moldability,adhesion, and the spreading on an interface at the time of bonding.

[0125] (iv) Molecular Weight Distribution (Mw/Mn)

[0126] The molecular weight distribution (Mw/Mn) of theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A), asmeasured by GPC, is in the range of 3 to 100, preferably 3.3 to 75, morepreferably 3.5 to 50.

[0127] When the molecular weight distribution (Mw/Mn) is in the aboverange, there can be obtained a rubber composition having excellentprocessability and being capable of providing a crosslinked rubbermolded product excellent in strength properties.

[0128] (v) Effective Network Chain Density (ν) (Indication ofCrosslinking Density)

[0129] The effective network chain density (ν), as measured after theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A) ispress crosslinked at 170° C. for 10 min using 0.01 mol ofdicumylperoxide based on 100 g of the copolymer rubber (A), is 0.5×10²⁰chains/cm³ or more, preferably 0.8×10²⁰ chains/cm³ or more, morepreferably 1.0×10²⁰ chains/cm³.

[0130] When the effective network chain density (ν) is 0.5×10²⁰chains/cm³ or more, there can be obtained a rubber composition capableof providing a crosslinked rubber molded product excellent incompression set resistance.

[0131] The ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) can be obtained by random copolymerizing ethylene, anα-olefin of 3 to 20 carbon atoms and a terminal vinyl group-containingnorbornene compound of the formula (I) or (II) in the presence of acatalyst containing compounds (H) and (I) described below as maincomponents under the conditions of a polymerization temperature of 30 to60° C., specifically 30 to 59° C., a polymerization pressure of 4 to 12kgf/cm², specifically 5 to 8 kgf/cm², and a feed rate molar ratio(non-conjugated polyene/ethylene) of the non-conjugated polyene toethylene of from 0.01 to 0.2. The copolymerization is preferablyconducted in a hydrocarbon medium.

[0132] (H) A soluble vanadium compound represented by the formula:VO(OR)_(n)X_(3−n) wherein R is a hydrocarbon group, X is a halogen atom,and n is 0 or an integer of 1 to 3, or a vanadium compound representedby the formula: VX₄ wherein X is a halogen atom.

[0133] The soluble vanadium compound (H) is soluble in a hydrocarbonmedium of the polymerization reaction system. Specific examples arevanadium compounds represented by the formula: VO(OR)aXb, or V(OR)cXdwherein R is a hydrocarbon group, 0≦a≦3, 0≦b≦3, 2≦a+b≦3, 0≦c≦4, 0≦d≦4,and 3≦c+d≦4; and electron donor adducts of these.

[0134] More specifically, there can be mentioned VOCl₃, VO(OC₂H₅)Cl₂,VO(OC₂H₅)₂Cl, VO(O-iso-C₃H₇)Cl₂, VO(O-n-C₄H₉)Cl₂, VO(OC₂H₅)₃, VOBr₃,VCl₄, VOCl₃, VO(O-n-C₄H₉)₃, and VCl₃.2OC₆H₁₂OH.

[0135] (I) An organoaluminum compound represented by the formula:R′_(m)AlX′_(3−m) wherein R′ is a hydrocarbon group, X′ is a halogenatom, and m is 1 to 3.

[0136] Examples of the organoaluminum compound (I) include:

[0137] trialkylaluminums, such as triethylaluminum, tributylaluminum,and triisopropylaluminum;

[0138] dialkylaluminum alkoxides, such as diethylaluminum ethoxide, anddibutylaluminum botoxide;

[0139] alkylaluminum sesquialkoxides, such as ethylaluminumsesquiethoxide, and butylaluminum sesquibutoxide;

[0140] partially alkoxylated alkylaluminums having average composition,represented by R¹ _(0.5)Al(OR′)_(0.5);

[0141] dialkylaluminum halides, such as diethylaluminum chloride,dibutylaluminum chloride, and diethylaluminum bromide;

[0142] partially halogenated alkylaluminums, such as alkylaluminumsesquihalides (e.g., ethylaluminum sesquichloride, butylaluminumsesquichloride, ethylaluminum sesquibromide), and alkylaluminumdihalides (e.g., ethylaluminum dichloride, propylaluminum dichloride,butylaluminum dibromide);

[0143] partially hydrogenated alkylaluminums, such as dialkylaluminumhydrides (e.g., diethylaluminum hydride, dibutylaluminum hydride), andalkylaluminum dihydrides (e.g., ethylaluminum dihydride, propylaluminumdihydride); and

[0144] partially alkoxylated and halogenated alkylaluminums, such asethylaluminum ethoxychloride, butylaluminum butoxychloride, andethylaluminum ethoxybromide.

[0145] In the present invention, a soluble vanadium compound representedby VOCl₃ selected from the compounds (H) and a blend of Al(OC₂H₅)₂Cl andAl₂(OC₂H₅)₃Cl₃ (blending ratio: not less than1/5=Al(OC₂H₅)₂Cl/Al₂(OC₂H₅)₃Cl₃) selected from the compounds (I) arepreferably used as the catalyst components, whereby anethylene/α-olefin/non-conjugated polyene random copolymer rubber (A)having an insoluble content of 1% or less after Soxhlet extraction(solvent: boiling xylene, extraction time: 3 hr, mesh: 325) can beobtained.

[0146] As the catalyst for the copolymerization, a “metallocenecatalyst”, as disclosed in, for example, Japanese Patent Laid-OpenApplication No. 9(1997)-40586, may be used.

[0147] The ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) for use in the invention may be graft-modified with a polarmonomer such as unsaturated carboxylic acid, or a derivative thereof(e.g., acid anhydride, ester).

[0148] Examples of the unsaturated carboxylic acids include acrylicacid, methacrylic acid, maleic acid, fumaric acid, itaconic acid,citraconic acid, tetrahydrophthalic acid andbicyclo(2,2,1)hept-2-ene-5,6-dicarboxylic acid.

[0149] Examples of the acid anhydrides of unsaturated carboxylic acidinclude maleic anhydride, itaconic anhydride, citraconic anhydride,tetrahydrophthalic anhydride, andbicyclo(2,2,1)hept-2-ene-5,6-dicarboxylic anhydride. Among these, maleicanhydride is preferable.

[0150] Examples of the unsaturated carboxylic esters include methylacrylate, methyl methacrylate, dimethyl maleate, monomethyl maleate,dimethyl fumarate, dimethyl itaconate, diethyl citraconate, dimethyltetrahydrophthalate, and dimethylbicyclo(2,2,1)hept-2-ene-5,6-dicarboxylate. Among these, methyl acrylateand ethyl acrylate are preferable.

[0151] The graft modifiers (graft monomers), such as the aboveunsaturated carboxylic acids, are used singly or in combination of twoor more kinds. In any case, they are used in an amount of 0.1 mol orless based on 100 g of the ethylene/α-olefin/non-conjugated polyenecopolymer rubber before the graft modification.

[0152] When the ethylene/α-olefin/non-conjugated polyene randomcopolymer rubber (A) having the above graft amount is used, a rubbercomposition having excellent flowability (molding processability) andcapable of providing a crosslinked rubber molded product havingexcellent low-temperature resistance can be obtained.

[0153] The graft-modified ethylene/α-olefin/non-conjugated polyenerandom copolymer rubber (A) can be obtained by allowing the unmodifiedethylene/α-olefin/non-conjugated polyene random copolymer rubber toreact with the unsaturated carboxylic acid or its derivative in thepresence of a radical initiator.

[0154] The graft reaction may be carried out in a solution state or amolten state. In case of the graft reaction in a molten state, it ismost effective and preferable to conduct continuously in an extruder.

[0155] Examples of the radical initiator used in the graft reactioninclude:

[0156] dialkyl peroxides, such as dicumyl peroxide, di-t-butyl peroxide,di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butylcumyl peroxide,di-t-amyl peroxide, t-butylhydro peroxide,2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3,2,5-dimethyl-2,5-di(benzoylperoxy)hexane,2,5-dimethyl-2,5-di(t-butylperoxy)hexane, andα,α′-bis(t-butylperoxy-m-isopropyl)benzene;

[0157] peroxy esters, such as t-butyl peroxyacetate, t-butylperoxyisobutyrate, t-butyl peroxypivalate, t-butyl peroxymaleate,t-butyl peroxyneodecanoate, t-butyl peroxybenzoate, and di-t-butylperoxynaphthalate;

[0158] ketone peroxides, such as dicyclohexanone peroxide; and

[0159] mixtures thereof. Among these, preferable are organic peroxideshaving a temperature at which the half-life period corresponds to oneminute, of 130 to 200° C. Highly preferable are dicumyl peroxide,di-t-butyl peroxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane,t-butylcumyl peroxide, di-t-amylperoxide, and t-butylhydro peroxide.

[0160] Examples of the polar monomers other than the unsaturatedcarboxylic acids and derivatives thereof (e.g., acid anhydrides, esters)include hydroxyl group-containing ethylenically unsaturated compounds,amino group-containing ethylenically unsaturated compounds, epoxygroup-containing ethylenically unsaturated compounds, aromatic vinylcompounds, vinyl ester compounds and vinyl chloride.

SiH Group-containing Compound (B)

[0161] The SiH group-containing compound (B) used in the presentinvention reacts with the ethylene/α-olefin/non-conjugated polyenerandom copolymer rubber (A), and works as a crosslinking agent. There isno specific limitation on the molecular structure of the SiHgroup-containing compound (B), and conventionally-produced resins, suchas those of linear, cyclic, branched and three-dimensional networkstructures, are also employable. However, they are conditioned tocontain at least two (preferably 3 or more) hydrogen atoms bondeddirectly to silicon atoms, namely, SiH groups, in one molecule.

[0162] As the SiH group-containing compound (B), usually employable is acompound represented by the following composition formula:

R⁴ _(b)H_(c)SiO_((4−b−c)/2).

[0163] In the above formula, R⁴ is a substituted or unsubstitutedmonovalent hydrocarbon group of 1 to 10, particularly 1 to 8 carbonatoms, excluding an aliphatic unsaturated bond. Examples of themonovalent hydrocarbon group include a phenyl group, halogen-substitutedalkyl groups, such as a trifluoropropyl group, and the alkyl groupspreviously exemplified with respect to R¹. Of these, preferable aremethyl, ethyl, propyl, phenyl, and trifluoropropyl groups, and highlypreferable are methyl and phenyl groups.

[0164] The letter b is a number satisfying the condition of 0≦b<3,preferably 0.6<b<2.2, highly preferably 1.5≦b≦2. The letter c is anumber satisfying the condition of 0<c≦3, preferably 0.002≦c<2, highlypreferably 0.01≦c≦1. The sum of b and c is a number satisfying thecondition of 0<b+c≦3, preferably 1.5<b+c≦2.7.

[0165] The SiH group-containing compound (B) is an organohydrogenpolysiloxane having preferably 2 to 1000 silicon atoms, particularlypreferably 2 to 300 silicon atoms, most preferably 4 to 200 siliconatoms, in one molecule. Specific examples of such compounds include:

[0166] siloxane oligomers, such as 1,1,3,3-tetramethyldisiloxane,1,3,5,7-tetramethyltetracyclosiloxane, and1,3,5,7,8-pentamethylpentacyclosiloxane;

[0167] methylhydrogenpolysiloxane terminated with trimethylsiloxy groupsat the both ends of molecular chain; adimethylsiloxane/methylhydrogensiloxane copolymer terminated withtrimethylsiloxy groups at the both ends of molecular chain;methylhydrogenpolysiloxane terminated with silanol groups at the bothends of molecular chain; a dimethylsiloxane/methylhydrogensiloxanecopolymer terminated with silanol groups at the both ends of molecularchain; dimethylpolysiloxane terminated with dimethylhydrogensiloxygroups at the both ends of molecular chain; methylhydrogenpolysiloxaneterminated with dimethylhydrogensiloxy groups at the both ends ofmolecular chain; a dimethylsiloxane/methylhydrogensiloxane copolymerterminated with dimethylhydrogensiloxy groups at the both ends ofmolecular chain; and

[0168] silicon resins comprising R⁴ ₂(H)SiO_(1/2) units and SiO_(4/2)units, and arbitrarily containing R⁴ ₃SiO_(1/2) units, R⁴ ₂SiO_(2/2)units, R⁴(H)SiO_(2/2) units, (H)SiO_(3/2) units, or R⁴SiO_(3/2) units.

[0169] As the methylhydrogenpolysiloxane terminated with trimethylsiloxygroups at the both ends of molecular chain, there can be mentionedcompounds represented by the following formula, and compounds of thesame formula in which methyl groups are partially or totally substitutedwith ethyl, propyl, phenyl, or trifluoropropyl groups:

(CH₃)₃SiO—(—SiH(CH₃)—O—)_(d)—Si(CH₃)₃

[0170] wherein d is an integer of 2 or more.

[0171] As the dimethylsiloxane/methylhydrogensiloxane copolymerterminated with trimethylsiloxy groups at the both ends of molecularchain, there can be mentioned compounds represented by the followingformula, specifically compounds of the same formula in which methylgroups are partially or totally substituted with ethyl, propyl, phenyl,or trifluoropropyl groups:

(CH₃)₃SiO—(—Si(CH₃)₂—O—)_(e)—(—SiH(CH₃)—O—)_(f)—Si(CH₃)₃,

[0172] wherein e is an integer of 1 or more, and f is an integer of 2 ormore.

[0173] As the methylhydrogenpolysiloxane terminated with silanol groupsat the both ends of molecular chain, there can be mentioned compoundsrepresented by the following formula, and compounds of the same formulain which methyl groups are partially or totally substituted with ethyl,propyl, phenyl, or trifluoropropyl groups:

HOSi(CH₃)₂O—(—SiH (CH₃)—O—)₂—Si(CH₃)₂OH.

[0174] As the dimethylsiloxane/methylhydrogensiloxane copolymerterminated with silanol groups at the both ends of molecular chain,there can be mentioned compounds represented by the following formula,and compounds of the same formula in which methyl groups are partiallyor totally substituted with ethyl, propyl, phenyl, or trifluoropropylgroups:

HOSi(CH₃)₂O—(—Si(CH₃)₂—O—)_(e)—(—SiH(CH₃)—O—)_(f)—Si(CH₃)₂OH,

[0175] wherein e is an integer of 1 or more, and f is an integer of 2 ormore.

[0176] As the dimethylpolysiloxane terminated withdimethylhydrogensiloxy groups at the both ends of molecular chain, therecan be mentioned compounds represented by the following formula, andcompounds of the same formula in which methyl groups are partially ortotally substituted with ethyl, propyl, phenyl, or trifluoropropylgroups:

HSi(CH₃)₂—(Si(CH₃)₂—O—)_(e)Si(CH₃)₂H,

[0177] wherein e is an integer of 1 or more.

[0178] As the methylhydrogenpolysiloxane terminated withdimethylhydrogensiloxy groups at the both ends of molecular chain, therecan be mentioned compounds represented by the following formula, andcompounds of the same formula in which methyl groups are partially ortotally substituted with ethyl, propyl, phenyl, or trifluoropropylgroups:

HSi(CH₃)₂O—(—SiH (CH₃)—O—)_(e)—Si(CH₃)₂H,

[0179] wherein e is an integer of 1 or more.

[0180] As the dimethylsiloxane/methylhydrogensiloxane copolymerterminated with dimethylhydrogensiloxy groups at the both ends ofmolecular chain, there can be mentioned compounds represented by thefollowing formula, and compounds of the same formula in which methylgroups are partially or totally substituted with ethyl, propyl, phenyl,or trifluoropropyl groups:

HSi(CH₃)₂O—(—Si(CH₃)₂—O—)_(e)—(—SiH(CH₃)—O—)_(h)—Si(CH₃)₂H,

[0181] wherein e and h are each an integer of 1 or more.

[0182] The above compounds can be prepared by conventional processes.For example, octamethylcyclotetrasiloxane and/ortetramethylcyclotetrasiloxane, and a compound containing atriorganosilyl group or a diorganohydrogensiloxy group, to be a terminalgroup, such as hexamethyldisiloxane or1,3-dihydro-1,1,3,3-tetramethyldisiloxane, are equilibrated at atemperature of about −10° C. to about +40° C. in the presence of acatalyst, such as sulfuric acid, trifluoromethanesulfonic acid ormethanesulfonic acid.

[0183] The SiH group-containing compound (B) is used in an amount of 0.1to 100 parts by weight, preferably 0.1 to 75 parts by weight, morepreferably 0.1 to 50 parts by weight, even more preferably 0.2 to 30parts by weight, highly preferably 0.2 to 20 parts by weight,particularly preferably 0.5 to 10 parts by weight, most preferably 0.5to 5 parts by weight, based on 100 parts by weight of theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A).When the SiH group-containing compound (B) is used in the above amount,there can be obtained a rubber composition capable of forming acrosslinked rubber molded product having a moderate crosslink density,excellent strength properties and elongation properties as well assatisfactory compression set resistance. The use of the SiHgroup-containing compound (B) in an amount exceeding 100 parts by weightis unfavorable because of disadvantageous cost.

[0184] The ratio of the SiH group to aliphatic unsaturated groupsparticipating in the crosslinking of theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A)(SiH group/aliphatic unsaturated group), is in the range of 0.2 to 20,preferably 0.5 to 10, particularly preferably 0.7 to 5.

Catalyst (C)

[0185] The catalyst (C) for optional use in the present invention, is anaddition reaction catalyst. There is no specific limitation on thecatalyst as far as it accelerates the addition reaction (hydrosilylationof alkene) of the alkenyl group of the ethylene/α-olefin/non-conjugatedpolyene random copolymer rubber (A) with the SiH group of the SiHgroup-containing compound (B). For example, addition reaction catalystscomprising platinum group elements (i.e., Group 8 metal type catalystsof Group 8 metals of the Periodic Table, Group 8 metal complexes orGroup 8 metal compounds), such as a platinum catalyst, a palladiumcatalyst and a rhodium catalyst, are employable. Of these, the platinumcatalyst is preferable.

[0186] As the platinum catalyst, a known platinum catalyst for use inaddition curing is generally used. For example, a finely dividedmetallic platinum catalyst described in U.S. Pat. No. 2,970,150, achloroplatinic acid catalyst described in U.S. Pat. No. 2,823,218, acomplex compound of platinum and hydrocarbon described in U.S. Pat. Nos.3,159,601 and 159,662, a complex compound of chloroplatinic acid and anolefin described in U.S. Pat. No. 3,516,946, and a complex compound ofplatinum and vinylsiloxane described in U.S. Pat. Nos. 3,775,452 and3,814,780 are employable. More specifically, there can be mentionedplatinum (platinum black), chloroplatinic acid, a platinum/olefincomplex, a platinum/alcohol complex, and platinum supported on a carriersuch as alumina or silica.

[0187] Examples of the palladium catalysts include palladium, apalladium compound and chloropalladate. Examples of the rhodiumcatalysts include rhodium, a rhodium compound and chlororhodate.

[0188] Other exemplary catalysts (C) are Lewis acids and cobaltcarbonyl.

[0189] The catalyst (C) is used, in terms of Pt metal, in an amount of0.1 to 100,000 ppm by weight, preferably 0.1 to 10,000 ppm by weight,more preferably 1 to 5,000 ppm by weight, particularly preferably 5 to1,000 ppm by weight, based on the ethylene/α-olefin/non-conjugatedpolyene random copolymer rubber (A).

[0190] When the catalyst (C) is used in the above amount, there can beobtained a rubber composition capable of forming a crosslinked rubbermolded product having moderate crosslink density, excellent strengthproperties and elongation properties. The use of catalyst (C) in anamount exceeding 100,000 ppm by weight is unfavorable because ofdisadvantageous cost.

[0191] In this invention, it is also possible to obtain a crosslinkedrubber molded product by irradiating an uncrosslinked rubber moldedproduct of a rubber composition containing no catalyst (C) , with light,y rays or electron rays.

Reaction Inhibitor (D)

[0192] In the present invention, the reaction inhibitor (D) isoptionally used together with the catalyst (C) Examples of the reactioninhibitor (D) include benzotriazol, ethynyl group-containing alcohols(e.g., ethynylcyclohexanol), acrylonitrile, amide compounds (e.g.,N,N-diallylacetamide, N,N-diallylbenzamide,N,N,N′,N′-tetraallyl-o-phthalic acid diamide,N,N,N′,N′-tetraallyl-m-phthalic acid diamide,N,N,N′,N′-tetraallyl-p-phthalic acid diamide), sulfur, phosphorus,nitrogen, amine compounds, sulfur compounds, phosphorus compounds, tin,tin compounds, tetramethyltetravinylcyclotetrasiloxane, and organicperoxides, such as hydroperoxide.

[0193] The reaction inhibitor (D) is used in an amount of 0 to 50 partsby weight, generally 0.0001 to 50 parts is by weight, preferably 0.001to 30 parts by weight, more preferably 0.005 to 20 parts by weight, evenmore preferably 0.01 to 10 parts by weight, highly preferably 0.05 to 5parts by weight, based on 100 parts by weight of theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A).

[0194] The use of the reaction inhibitor (D) in an amount of 50 parts byweight or less inhibits the early crosslinking reaction to assure timenecessary for molding, whereby a rubber composition excellent inproductivity to produce a crosslinked rubber molded product, can beobtained. The use of the reaction inhibitor (D) in an amount exceeding50 parts by weight is unfavorable because of disadvantageous cost.

Silane Coupling Agent (E)

[0195] In the present invention, the silane coupling agent (E) isoptionally used together with the catalyst (C) , in order to bondpolymers with an interface of a filler and improve the self-adhesion ofthe rubber composition. As the silane coupling agent (E), there can bementioned a (meth)acryl functional silane coupling agent, an epoxyfunctional silane coupling agent, a vinyl functional silane couplingagent, and an amino (imino) functional silane coupling agent.

[0196] Specific examples of the (meth)acryl functional silane couplingagent include:

[0197] 3-methacryloxypropyl trimethoxysilane,

[0198] 3-methacryloxypropyl triethoxysilane,

[0199] 3-acryloxypropyl trimethoxysilane,

[0200] 3-acryloxypropyl triethoxysilane,

[0201] methacryloxymethyl trimethoxysilane,

[0202] methacryloxymethyl triethoxysilane,

[0203] acryloxymethyl trimethoxysilane, and

[0204] acryloxymethyl triethoxysilane.

[0205] Specific examples of the epoxy functional silane coupling agentinclude:

[0206] 3-glycidoxypropyl trimethoxysilane,

[0207] 3-glycidoxypropyl triethoxysilane,

[0208] 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane,

[0209] 2-(3,4-epoxycyclohexyl)ethyl triethoxysilane,

[0210] γ-glycidoxypropyl trimethoxysilane, and

[0211] γ-glycidoxypropyl methyldiethoxysilane.

[0212] Specific examples of the vinyl functional silane coupling agentinclude:

[0213] vinyl trimethoxysilane, vinyl triethoxysilane, and

[0214] vinyl tris(β-methoxyethoxy)silane.

[0215] Specific examples of the amino (imino) functional silane couplingagent include:

[0216] amino and/or imino group-containing alkoxysilane, such asH₂NCH₂CH₂CH₂Si(OCH₃)₃, H₂NCH₂CH₂NHCH₂CH₂CH₂Si(OCH₃)₃,H₂NCH₂CH₂NHCH₂CH₂CH₂Si(CH₃)(OCH₃)₂, and(C₂H₅O)₃Si(CH₂)₃NH(CH₂)₂NH(CH₂)₃Si(OH₂H₅)₃;

[0217] reaction products of the amino and/or imino group-containingalkoxysilane and an epoxysilane compound represented, for example, bythe following formulas:

[0218] reaction products of the amino and/or imino group-containingalkoxysilane and a methacryloxysilane compound, such asCH₂═C(CH₃)COOCH₂CH₂CH₂Si(OCH₃)₃, andCH₂═C(CH₃)COOCH₂CH₂CH₂Si(OCH₂CH₂OCH₃)₃; and

[0219] N-phenyl-γ-aminopropyltrimethoxysilane.

[0220] Among these silane coupling agents, preferable are:

[0221] vinyl functional silane coupling agents, such as vinyltrimethoxysilane, vinyl triethoxysilane, and vinyltris(β-methoxyethoxy)silane;

[0222] epoxy functional silane coupling agents, such as3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane,2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane,2-(3,4-epoxycyclohexyl)ethyl triethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyl methyldiethoxysilane, andN-phenyl-γ-aminopropyl trimethoxysilane; and

[0223] (meth)acryl functional silane coupling agents, such as3-methacryloxypropyl trimethoxysilane, and 3-methacryloxypropyltriethoxysilane.

[0224] The silane coupling agent (E) is used in an amount of preferably0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight,based on the sum 100 parts by weight of theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A) andthe SiH group-containing compound (B).

Plasticizer (F)

[0225] The plasticizer (F) is optionally used together with the catalyst(C), for example, a softener generally used for rubbers is employable.

[0226] Specific examples of the plasticizer include:

[0227] petroleum softeners, such as paraffin process oils, naphtheneprocess oils, aromatic process oils, an ethylene/α-olefin cooligomer,paraffin wax, liquid paraffin, white oil, petrolatum, lubricating oil,oil asphalt, and vaseline;

[0228] coal tar softeners, such as coal tar, and coal tar pitch;

[0229] aliphatic softeners, such as castor oil, linseed oil, rapeseedoil, and coconut oil;

[0230] tall oil;

[0231] synthetic polymer substances, such as petroleum resin, atacticpolypropylene, and coumarone-indene resin; and

[0232] phthalic acid derivatives, isophthalic acid derivatives,tetrahydrophthalic acid derivatives, adipic acid derivatives, azelaicacid derivatives, sebacic acid derivatives, dodecane-2-acid derivatives,maleic acid derivatives, fumaric acid derivatives, trimellitic acidderivatives, pyromellitic acid derivatives, citric acid derivatives,itaconic acid derivatives, oleic acid derivatives, ricinoleic acidderivatives, stearic acid derivatives, phosphoric acid derivatives,sulfonic acid derivatives, glycerin derivatives, glutaric acidderivatives, epoxy derivatives, glycol derivatives, paraffinderivatives, and silicone oils.

[0233] Among these, preferable are the ethylene/α-olefin cooligomer,process oils, and paraffin derivatives which do not inhibit thesilylation. Particularly preferable are paraffin process oils and anethylene/α-olefin cooligomer.

[0234] The plasticizer (F) is used in an amount of 0 to 1,000 parts byweight, usually 1 to 1,000 parts by weight, preferably 5 to 800 parts byweight, more preferably 10 to 700 parts by weight, even more preferably20 to 500 parts by weight, highly preferably 30 to 300 parts by weight,based on 100 parts by weight of the ethylene/α-olefin/non-conjugatedpolyene random copolymer rubber (A).

[0235] The use of the plasticizer (F) in the above amount leads toimprovement in flowability and, therefore, moldability. The use of theplasticizer (F) in an amount exceeding 1,000 parts by weightdeteriorates the strength properties, and is therefore unfavorable.

Other Components

[0236] The second to the fourth crosslinkable rubber compositions of thepresent invention can be used in an uncrosslinked state. They, however,exhibit their properties most conspicuously when used as a crosslinkedproduct such as a crosslinked rubber molded product and a crosslinkedrubber expanded (foamed) product.

[0237] The second to the fourth crosslinkable rubber compositions of theinvention may contain, according to the intended uses thereof, knownadditives, such as a rubber reinforcing agent, an inorganic filler, ananti-aging agent, a processing aid, a vulcanization accelerator, anorganic peroxide, a crosslinking aid, a foaming agent, a foaming aid, acolorant, a dispersant, and a flame retardant, within the limit notdetrimental to the objects of the present invention.

[0238] The rubber reinforcing agent functions to enhance mechanicalproperties of the crosslinked rubbers, such as tensile strength, tearstrength, and abrasion resistance. As the reinforcing agents, there canbe mentioned carbon blacks, such as SRF, GPF, FEF, HAF, ISAF, SAF, FTand MT; the above carbon blacks surface-treated with a silane couplingagent or the like; finely divided silicic acid; and silica.

[0239] Examples of silica include fumed silica, and precipitated silica.The silica may be surface treated with reactive silane, such ashexamethyldisilazane, chlorosilane, and alkoxysilane; or low-molecularweight siloxane. The specific surface area (BED method) of the silica ispreferably 50 m²/g or more, more preferably 100 to 400 m²/g.

[0240] The type and the amount of the rubber reinforcing agent, can beappropriately determined according to its application. The rubberreinforcing agent is used in an amount of usually up to 300 parts byweight maximum, preferably up to 200 parts by weight maximum, based on100 parts by weight of the ethylene/α-olefin/non-conjugated polyenerandom copolymer rubber (A).

[0241] As the inorganic fillers, there can be mentioned light calciumcarbonate, heavy calcium carbonate, talc, and clay.

[0242] The type and the amount of the inorganic filler can beappropriately determined according to its application. The inorganicfiller is used in an amount of usually up to 300 parts by weightmaximum, preferably up to 200 parts by weight maximum, based on 100parts by weight of the ethylene/α-olefin/non-conjugated polyene randomcopolymer rubber (A).

[0243] As the anti-aging agent, there can be mentioned those of aminetype, hindered phenol type and sulfur type. The anti-aging agent is usedin an amount not detrimental to the objects of the present invention.

[0244] The amine type anti-aging agent for use in the present inventionare, for example, diphenylamines and phenylenediamines.

[0245] Examples of the diphenylamines includep-(p-toluenesulfonylamido)-diphenylamine, 4,4′-(α,α-dimethylbenzyl)diphenylamine, 4,4′-dioctyldiphenylamine, ahigh-temperature reaction product of diphenylamine and acetone, alow-temperature reaction product of diphenylamine and acetone, alow-temperature reaction product of diphenylamine, aniline and acetone,a reaction product of diphenylamine and diisobutylene, octylateddiphenylamine, dioctylated diphenylamine, p,p′-dioctyldiphenylamine, andalkylated diphenylamine.

[0246] Examples of the phenylenediamines include p-phenylenediamines,such as N,N′-diphenyl-p-phenylenediamine,n-isopropyl-N′-phenyl-p-phenylenediamine,N,N′-di-2-naphthyl-p-phenylenediamine,N-cyclohexyl-N′-phenyl-p-phenylenediamine,N-phenyl-N′-(3-methacryloyloxy-2-hydroxypropyl)-p-phenylenediamine,N,N′-bis(1-methylheptyl)-p-pheylenylenediamine,N,N′-bis(1,4-dimethylpentyl)-p-phenylenediamine,N,N′-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine,N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine,phenylhexyl-p-phenylenediamine, and phenyloctyl-p-phenylenediamine.

[0247] Among these, particularly preferable are4,4′-(α,α-dimethylbenzyl)diphenylamine andN,N′-di-2-naphthyl-p-phenylenediamine.

[0248] These compounds can be used singly or in combination of 2 or morekinds.

[0249] Examples of the hindered phenol type anti-aging agent include:

[0250] (1) 1,1,3-tris-(2-methyl-4-hydroxy-5-t-butylphenyl)butane,

[0251] (2) 4,4′-butylidenebis-(3-methyl-6-t-butylphenol),

[0252] (3) 2,2-thiobis(4-methyl-6-t-butylphenol),

[0253] (4) 7-octadecyl-3-(4′-hydroxy-3′,5′-di-t-butylphenyl)propionate,

[0254] (5)tetrakis-(methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate)methane,

[0255] (6)pentaerythritol-tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate),

[0256] (7) triethyleneglycol-bis(3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate),

[0257] (8)1,6-hexanediol-bis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate),

[0258] (9)2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine,

[0259] (10) tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate,

[0260] (11)2,2-thio-diethylenebis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate),

[0261] (12)N,N′-hexamethylenebis(3,5-di-t-butyl-4-hydroxy)-hydrocinnamide,

[0262] (13) 2,4-bis((octylthio)methyl)-o-cresol,

[0263] (14) 3,5-di-t-butyl-4-hydroxybenzyl-phosphonate-diethyl ester,

[0264] (15)tetrakis(methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate))methane,

[0265] (16) octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, and

[0266] (17)3,9-bis(2-(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-dimethylethyl)-2,4-8,10-tetraoxaspiro(5,5)undecane.

[0267] Of these, preferable are the phenol compounds (5) and (17).

[0268] Examples of the sulfur type anti-aging agent include thosegenerally used in rubbers.

[0269] Specific examples of the sulfur type anti-aging agent include:

[0270] imidazole type anti-aging agents, such as2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole,2-mercaptomethylbenzimidazole, zinc salt of2-mercaptomethylbenzimidazole and zinc salt of2-mercaptomethylimidazole; and

[0271] aliphatic thioether type anti-aging agents, such as dimyristylthiodipropionate, dilauryl thiodipropionate, distearyl thiodipropionate,ditridecyl thiodipropionate andpentaerythritol-tetrakis-(β-lauryl-thiopropionate). Among these,preferable are 2-mercaptobenzimidazole, zinc salt of2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, zinc salt of2-mercaptomethylbenzimidazole andpentaerythritol-tetrakis-(β-lauryl-thiopropionate).

[0272] As the processing aid, compounds generally used in rubbers areemployable.

[0273] Examples of the processing aid include:

[0274] higher fatty acids, such as ricinoleic acid, stearic acid,palmitic acid, and lauric acid;

[0275] salts of higher aliphatic acids, such as barium stearate, zincstearate and calcium stearate; and

[0276] esters of higher fatty acids, such as ricinoleic acid, stearicacid, palmitic acid and lauric acid.

[0277] The processing aid is used in an amount of usually 10 parts byweight or less, preferably 5 parts by weight or less, based on 100 partsby weight of the ethylene/α-olefin/non-conjugated polyene randomcopolymer rubber (A). The optimum amount thereof is appropriatelydetermined in accordance with the required property values.

[0278] In this invention, an organic peroxide may be used in addition tothe catalyst (C) to conduct both of addition crosslinking and radicalcrosslinking. The organic peroxide is used in an amount of about 0.1 toabout 10 parts by weight based on 100 parts by weight of theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A). Asthe organic peroxides for use herein, conventional organic peroxidesusually employed in rubber crosslinking are employable.

[0279] When the organic peroxide is used, a crosslinking assistant ispreferably used in combination.

[0280] Examples of the crosslinking assistant include: sulfur; quinondioxime compounds, such as p-quinon dioxime; methacrylate compounds,such as polyethylene glycol dimethacrylate; allyl compounds, such asdiallyl phthalate, and triallyl cyanurate; maleimide compounds; anddivinylbenzene.

[0281] The crosslinking assistant is used in an amount of 0.5 to 2 molbased on 1 mol of the organic peroxide to be used, preferably aboutequimolar amount.

[0282] As the foaming agent, there can be mentioned:

[0283] inorganic foaming agents, such as sodium bicarbonate, sodiumcarbonate, ammonium bicarbonate, ammonium carbonate, and ammoniumnitrite;

[0284] nitroso compounds, such asN,N′-dimethyl-N,N′-dinitrosoterephthalamide, andN,N′-dinitrosopentamethylenetetramine;

[0285] azo compounds, such as azodicarbonamide, azobisisobutyronitrile,azocyclohexylnitrile, azodiaminobenzene, and barium azodicarboxylate;

[0286] sulfonyl hydrazide compounds, such as benzenesulfonyl hydrazide,toluenesulfonyl hydrazide, p,p′-oxybis(benzenesulfonyl hydrazide), anddiphenylsulfone-3,3′-disulfonyl hydrazide;

[0287] azide compounds, such as calcium azide, 4,4-diphenyldisulfonylazide, and p-toluenesulfonyl azide; and

[0288] gases, such as carbon dioxide, nitrogen, oxygen, andchlorofluorocarbons.

[0289] The foaming agent is used in an amount of 0.5 to 30 parts byweight, preferably 1 to 20 parts by weight, based on 100 parts by weightof the ethylene/α-olefin/non-conjugated polyene random copolymer rubber(A). The use of the foaming agent in the above amount enables productionof a foamed product having an apparent specific gravity of 0.03 to 0.8g/cm³. The optimum amount thereof is appropriately determined inaccordance with the required property values.

[0290] A foaming aid may be used in combination with the foaming agentif necessary. The foaming aid has functions of lowering thedecomposition temperature of the foaming agent, accelerating thedecomposition, and uniformalization of air bubbles.

[0291] Examples of the foaming aid include organic acids, such assalicylic acid, phthalic acid, stearic acid, and oxalic acid; urea andderivatives thereof. The foaming aid is used in an amount of 0.01 to 10parts by weight, preferably 0.1 to 5 parts by weight, based on 100 partsby weight of the ethylene/α-olefin/non-conjugated polyene randomcopolymer rubber (A). The optimum amount thereof is appropriatelydetermined in accordance with the required property values.

[0292] According to the present invention, known rubbers may be blendedin the second to the fourth crosslinkable rubber compositions within thelimit not detrimental to the objects of the invention.

[0293] Examples of such rubbers include natural rubber (NR), isoprenerubbers such as isoprene rubber (IR); and conjugated diene rubbers, suchas butadiene rubber (BR), styrene-butadiene rubber (SBR),acrylonitrile-butadiene rubber (NBR) , and chloroprene rubber (CR).

[0294] Hitherto known ethylene/α-olefin copolymer rubbers can also beused. For example, an ethylene/propylene random copolymer (EPR), and anethylene/α-olefin/polyene copolymer (EPDM or the like) other than theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A),are usable.

Rubber Compositions and uses Thereof

[0295] The first to the fourth crosslinkable rubber compositions of thisinvention are used for electric and electronic parts, transportationmachines, civil engineering and construction items, medical appliancesand goods for leisure activities.

[0296] Uses for the electric and electronic parts include sealing,potting and coating materials and adhesives respectively applied toheavy electric apparatus parts, light electrical appliance parts, orcircuits and substrates of electric and electronic machinery and tools;repairing materials for covered electric wire; insulating sealingmaterials for electric wire joint parts; rolls for office automationequipments; vibration absorbing materials; and gels or encapsulationmaterials for condensers.

[0297] The sealing materials are suitably used for refrigerators,freezers, washing machines, gas meters, microwaves, steam irons andcircuit breakers.

[0298] The potting materials are suitably used for potting transformerhigh-tension circuits, printed boards, high voltage transformersequipped with a variable resistor, electric insulating parts,semi-conductive parts, conductive parts, solar cells, and TV fly-backtransformers.

[0299] The coating materials are suitably used for coating circuitelements, such as a high voltage thick film resistor and a hybrid IC;HIC; electrical insulating parts; semi-conductive parts; conductiveparts; modules; printed circuits; ceramic boards; buffer materials fordiodes, transistors and bonding wires; semi-conductive elements; andoptical fibers for optical communication.

[0300] The adhesives are suitably used for bonding cathode-ray tubewedges or necks, electric insulating parts, semi-conductive parts andconductive parts.

[0301] The transportation machines include automobiles, ships, airplanesand railway vehicles.

[0302] Uses for the automobiles include sealing materials for gaskets ofautomobile engines, electric trim parts and oil filters; pottingmaterials for an ignitor HIC and automotive hybrid IC; coating materialsfor automobile bodies, automobile window glass and engine controlsubstrates; and adhesives for gaskets of oil pans, timing belt covers,automotive moles, head lamp lenses, sun roof seals and mirrors.

[0303] Uses for the ships include sealing materials for wire connectingdistributor boxes, electric system parts and electric wires; andadhesives for electric wires and glass.

[0304] Uses for the civil engineering and construction include sealantsof building materials for butte joints in glass screen method ofcommercial buildings, joints of glass fringes fixed with sash, interiorfinishing joints of toilet facilities, lavatory and show cases, jointsof bath tub circumferences, outer wall extension jointsof-prefabrication houses, and joints of siding boards; sealing materialsfor double glazing units; civil engineering sealants used in roadmaintenance; coatings and adhesives for metals, glass, stones, slates,concretes and tiles; adhesive sheets; water proofing sheets; andvibration-proof sheets.

[0305] Uses for medical appliances include sealing materials formedicinal rubber stoppers, syringe gaskets and rubber stoppers forreducing blood pressure.

[0306] Uses for the goods for leisure activities include swimmingmaterials, such as swimming caps, diving masks and earplugs; and gelbuffer materials for sport shoes and baseball gloves.

[0307] The first to the fourth crosslinkable rubber compositions of thepresent invention can be suitably used as sealing, potting and coatingmaterials and adhesives respectively applied to electric and electronicparts, transportation machines, civil engineering and constructionmaterials, medical appliances and goods for leisure activities.

Preparation of Rubber Compositions and Crosslinked Rubber MoldedProducts Thereof

[0308] As mentioned above, the second to the fourth crosslinkable rubbercompositions of the present invention can be used in an uncrosslinkedstate. They, however, exhibit their properties most conspicuously whenused as a crosslinked product (vulcanized product) such as a crosslinkedrubber molded product and a crosslinked rubber foamed product.

[0309] The crosslinked product from any of the second to the fourthcrosslinkable rubber compositions of the invention may be produced, asin the usual room temperature-crosslinkable rubber (RTV rubber), bymixing the ethylene/α-olefin/ non-conjugated polyene random copolymerrubber (A), the SiH group-containing compound (B), and optionally, thecatalyst (C), the reaction inhibitor (D), the silane coupling agent (E)and the plasticizer (F), and according to the intended use of thecrosslinked product, conventional additives, such as a rubberreinforcing agent, an inorganic filler, an anti-aging agent, aprocessing aid, a vulcanization accelerator, an organic peroxide, acrosslinking assistant, a foaming agent, a foaming aid, a colorant, adispersant, and a flame retardant; molding the compounded rubber into adesired shape by filling it in a gap, applying it between objects,coating it on an object, or potting an object into it; and allowing itto stand at room temperature to conduct crosslinking (vulcanizing).Heating may be performed to accelerate the crosslinking reaction.

[0310] Specifically, the second to the fourth crosslinkable rubbercompositions of the present invention can be prepared by mixing theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A),the SiH group-containing compound (B), and optionally, the catalyst (C),the reaction inhibitor (D), the silane coupling agent (E) and theplasticizer (F), and according to the intended use of the crosslinkedproduct, conventional additives, such as a rubber reinforcing agent, aninorganic filler, an anti-aging agent, a processing aid, a vulcanizationaccelerator, an organic peroxide, a crosslinking assistant, a foamingagent, a foaming aid, a colorant, a dispersant, and a flame retardant,by using a kneading apparatus, such as a planetary mixer and a kneader.

[0311] According to the present invention, theethylene/α-olefin/non-conjugated polyene random copolymer rubber (A) canbe mixed with the rubber reinforcing agent, the inorganic filler and thelike at high temperatures. Meanwhile, when the SiH group-containingcompound (B) and the catalyst (C) are mixed simultaneously at hightemperatures, crosslinking (scorching) might occur. Therefore, if theSiH group-containing compound (B) and the catalyst (C) are mixed at thesame time, the kneading is preferably conducted at a temperature of 80°C. or below. When the SiH group-containing compound (B) and the catalyst(C) is added to the composition one by one, the kneading is carried outat a temperature exceeding 80° C. It is preferable in some cases to cooldown the heat generated by the kneading with water.

[0312] The thus prepared second to the fourth crosslinkable rubbercompositions of the invention are molded into a desired shape when theyare filled in a gap, applied between objects, coated on an object, orwhen an object is potted therein, otherwise by various molding methodsusing an extruder, a calendar roller, a press, an injection moldingmachine, a transfer molding machine, etc. The thus molded product isallowed to stand at room temperature to conduct crosslinking, whereby adesired crosslinked product (crosslinked rubber molded product) can beobtained. Further, heating may be performed to accelerate thecrosslinking reaction.

EFFECT OF THE INVENTION

[0313] The first crosslinkable rubber composition of the presentinvention has a high crosslinking rate at room temperature, excellentadhesion, especially with an inorganic substance such as metals, and iscapable of producing crosslinked rubber molded products (includingfoamed products) with satisfactory productivity. The products have hightensile elongation, and are excellent in weather, ozone, heat aging andcompression set resistances and in resistance to gas permeability.

[0314] The second to the fourth crosslinkable rubber compositions of thepresent invention have a high crosslinking rate at room temperature andexcellent productivity, excellent adhesion, especially with an inorganicsubstance such as metals, and are capable of producing, at low cost,crosslinked rubber molded products (including foamed products) excellentin weather, ozone, heat aging and compression set resistances and inresistance to gas permeability.

[0315] The first to the fourth crosslinkable rubber compositions of thepresent invention are preferably employed, by virtue of the above-notedproperties, for uses involving electric and electronic parts,transportation machines, civil engineering and construction materials,medical appliances and goods for leisure activities. Specific usesthereof are described hereinbefore. These rubber compositions haveexcellent moldability and adhesion in addition to the above properties,and are therefore preferable as a sealing material or the like.

EXAMPLES

[0316] Hereinafter, the present invention will be described in moredetail with reference to the following examples, however, they are notintended to limit the scope thereof.

[0317] With regard to the copolymer rubbers used in the examples andcomparative examples, the composition, iodine value, intrinsic viscosity[η], molecular weight distribution (Mw/Mn), effective network chaindensity (ν) and adhesion strength were determined with the followingmeasurements.

[0318] (1) Composition of copolymer rubber

[0319] The composition of a copolymer rubber was measured by the ¹³C-NMRmethod.

[0320] (2) Iodine value of copolymer rubber

[0321] The iodine value of a copolymer rubber was determined with thetitration method.

[0322] (3) Intrinsic viscosity [η] of copolymer rubber

[0323] The intrinsic viscosity of a copolymer rubber was measured indecalin at 135° C.

[0324] (4) Molecular Weight Distribution (Mw/Mn)

[0325] The molecular weight distribution of a copolymer rubber wasrepresented by the ratio (Mw/Mn) of a weight average molecular weight(Mw) to a number average molecular weight (Mn), determined by GPC. InGPC, GMH-HT and GMH-HTL (manufactured by Tosoh Co. Ltd.) were used ascolumns and orthodichlorobenzene was used as a solvent.

[0326] (5) Effective Network Chain Density (ν)

[0327] A polymer rubber was immersed in toluene at 37° C. for 72 hraccording to JIS K6258 (1993) and the effective network chain densitywas determined by the Flory-Rehner equation.

ν(chains/cm³)=ν_(R)+ln(1−ν_(R))+μν_(R) ² /−Vo(ν_(R) ^(⅓)−ν_(R)/2)

[0328] ν_(R): a fraction of a pure rubber volume to a volume of a purerubber swelled (pure rubber volume+absorbed solvent volume) in acrosslinked rubber swelled.

[0329] μ: a constant of rubber-solvent interaction=0.49

[0330] Vo: molar volume of a solvent.

[0331] ν: effective network chain density. The number of effectivenetwork chains in 1 cm³ of the pure rubber.

[0332] Preparation of sample: 0.01 mol of dicumylperoxide was added to100 g of a copolymer rubber and kneaded at a kneading temperature of 50°C. using a 8-inch roll open mill rolls in accordance with the methoddescribed in Society of Rubber Industry, Japan Standards (SRIS), and theresulting kneadate was crosslinked with press at 170° C. for 10 min toprepare a sample.

[0333] (6) Adhesion Strength

[0334] The composition as shown in below was prepared and the adhesionstrength thereof was measured in accordance with the tensile adhesivetest JIS A 5758(1986). As curing conditions, reactive curing 2-componenttype one was employed. Aluminum was selected as the adherend.

[0335] <Process for Preparing Composition>

[0336] Using a 2-liter planetary mixer (manufactured by InoueSeisakusho, Co., 100 parts by weight of one of various polymers and 20parts by weight of carbon black (Trade Mark Asahi#60G, manufactured byAsahi Carbon Co. were kneaded at 80° C. for 20 min. The filling rate was50%. The resulting blend was cooled to room temperature, and thenkneaded with 3 parts by weight of tris(dimethylhydrosiloxy)phenyl silane[C₆H₅—Si(O—SiH—(CH₃)₂)₃] at room temperature for 10 min and thereafterkneaded with 0.1 part by weight of hexachloro-platinic acid (2%isopropanol solution) at room temperature for 5 min to prepare acomposition.

Preparation Example 1

[0337] [Preparation of Ethylene/propylene/5-vinyl-2-norbornene randomcopolymer rubber (A-1)]

[0338] Using a 100-litter substantially internal volume-having stainlesspolymerizer equipped with stirring blades (number for revolutions=250rpm), terpolymerization of ethylene, propylene and 5-vinyl-2-norbornenewas carried out continuously. From the side inlet of the polymerizer, 601 /hr of hexane, 3.0 Kg/hr of ethylene, 9.0 Kg /hr of propylene and 550g/hr of 5-vinyl-2-norbornene, 50 1 /hr of hydrogen and, as a catalyst,95 mmol of VOCl₃, 443 mmol of Al(Et)₂Cl and 127 mmol/hr ofAl(Et)_(1.5)Cl_(1.5) were fed to a liquid phase continuously.

[0339] Carrying out copolymerization in the above-mentioned conditions,ethylene/propylene/5-vinyl-2-norbornene random copolymer rubber (A-1)was prepared in a uniform solution state.

[0340] Thereafter, a small amount of methanol was added to thepolymerization solution continuously drawn out from the bottom of thepolymerizer to stop the polymerization reaction. The polymer wasseparated from the solvent by a steam stripping treatment, and thendried in vacuo at 55° C. for 48 hr. The physical properties of theethylene/propylene/5-vinyl-2-norbornene random is copolymer rubber (A-1)thus prepared are shown in Table 1.

Preparation Examples 2-3

[0341] The procedure of Preparation Example 1 was repeated except thatthe polymerization conditions were changed to those as shown in Table 1to prepare ethylene/propylene/5-vinyl-2-norbornene random copolymerrubbers (A-2) and (A-3) having different properties. The physicalproperties of the resulting copolymer rubbers (A-2) and (A-3) are shownin Table 1. TABLE 1 Copolymer rubber A-1 A-2 A-3 CatalystVOCl₃—Al(Et)₂Cl/ VOCl₃—Al(Et)₂Cl/ VOCl₃—Al(Et)₂Cl/ Al(Et)_(1.5)Cl_(1.5)Al(Et)_(1.5)Cl_(1.5) Al(Et)_(1.5)Cl_(1.5) Al/V 6 6 6 Al(Et)₂Cl/ 7/2 7/27/2 Al(Et)_(1.5)Cl_(1.5) Polymerization 40 40 40 temperature (° C.)Polymerization 7.1 7.1 7.2 pressure (kgf/cm²) Catalyst feeding 95 45 90(mmol/h) Diene VNB VNB VNB Diene feeding (g/h) 550 330 550 α-olefinPropylene Propylene Propylene Ethylene/α-olefin 3.0/9.0 3.0/9.5 2.8/11.5 feeding (Kg/h) H₂ (NL/h) 70 50 40 Yield (Kg/h) 3.5 4.5 4.1Ethylene content 68 68 63 (mol %) [η] (dl/g) 0.2 0.7 1.1 IV (g/100 g) 1510 15 Mw/Mn 15 28 40 Effective network 0.8 1.2 2.5 chain density ν (×10¹⁹ chains/cm³)

Example 1

[0342] Firstly, 100 parts by weight of ethylene/α-olefin/non-conjugatedpolyene random copolymer rubber (A-1), 4.3 parts by weight ofC₆H₅Si(—OSiMe₂H)₃ (B) (manufactured by Shinetsu Chemical Industries Co.)and 0.3 part by weight of 2% isopropyl alcohol solution ofchloroplatinic acid (C) as shown in Table 1 were kneaded at roomtemperature using a laboratory plastomill to prepare a compoundedrubber.

[0343] The resulting compounded rubber was subjected to a gelation testand the gelation time at room temperature was measured. The results areshown in Table 3.

[0344] Further, the resulting compounded rubber was casted to a metallicframe in 2 mm depth and thereafter was allowed to stand at roomtemperature for 3 days to prepare a 2 mm thick crosslinked sheet.

[0345] With regard to the resulting crosslinked sheet, a tensile testand ozone deterioration test were carried out in accordance with thefollowing manners.

[0346] (1) Gelation Test

[0347] The change in frequency was measured using a scanning VNC (SVNC)(manufactured by Rapra Technology Ltd.). The frequency increased withproceeding of this measurement, and when it stabilized, it was taken tobe 100%. The time that the frequency changed 95% was taken as thegelation time (crosslinking time). The measuring temperature was roomtemperature and the measuring procedure was carried out according to thefollowing literatures.

[0348] (i) RAPRA Operation manual (Software Ver. 2.2) of Scanningvibrating needle type curemeter (scanning VNC)

[0349] (ii) RAPRA Curing comprehension (RTL/2844) Scanning vibratingneedle type curemeter (scanning VNC).

[0350] (2) Tensile Test

[0351] The tensile test was carried out at a measuring temperature of23° C. at a tensile rate of 500 mm/min in accordance with JIS K-6251,and when the crosslinked sheet was broken, tensile strength at break TBand tensile elongation E_(B) were measured.

[0352] (3) Ozone Deterioration Test

[0353] The ozone deterioration test was carried out in accordance withJIS K-5259. The test conditions are 40° C., 50 pphm of ozoneconcentration and 96 hr.

[0354] These results are shown in Table 2.

[0355] The adhesion strength of the composition ofethylene/α-olefin/non-conjugated polyene random copolymer rubber (A-1)to aluminum was measured in accordance with the above method. As aresult, the adhesion strength was 1.5 MPa.

Example 2

[0356] The procedure of Example 1 was repeated except thatethylene/propylene/5-vinyl-2-norbornene random copolymer rubber (A-2) asshown in Table 1 was used in place ofethylene/propylene/5-vinyl-2-norbornene random copolymer rubber (A-1) ,and 120 parts by weight of a plasticizer (F) [manufactured by IdemitsuKosan Co. Ltd. TradeMark: Idemitsu Diana process Oil PW-32] was added.The results are shown in Table 2.

[0357] The adhesion strength of the composition ofethylene/α-olefin/non-conjugated polyene random copolymer rubber (A-2)to aluminum was measured in accordance with the above method. As aresult, the adhesion strength was 2.5 MPa.

Example 3

[0358] The procedure of Example 1 was repeated except thatethylene/propylene/5-vinyl-2-norbornene random copolymer rubber (A-3) asshown in Table 1 was used in place ofethylene/propylene/5-vinyl-2-norbornene random copolymer rubber (A-1) ,and 300 parts by weight of a plasticizer (F) [manufactured by IdemitsuKosan Co. Ltd. TradeMark: Idemitsu Diana process Oil PW-32] was added.The results are shown in Table 2.

[0359] The adhesion strength of the composition ofethylene/α-olefin/non-conjugated polyene random copolymer rubber (A-3)to aluminum was measured in accordance with the above method. As aresult, the adhesion strength was less than 0.1 MPa

Example 4

[0360] The procedure of Example 2 was repeated except that 0.01 part byweight of ethynylcyclohexanol (D) and 5 parts by weight of3-glycidoxypropyl trimethoxysilane (E) were added. The results are shownin Table 2.

Example 5

[0361] The procedure of Example 3 was repeated except that the amount ofthe plasticizer (F) was changed from 300 parts by weight to 400 parts byweight, and 0.01 part by weight of ethynylcyclohexanol (D), 5 parts byweight of 3-glycidoxypropyl trimethoxysilane (E) and 50 parts by weightof silica [manufactured by Nippon Aerosil Co. Ltd. Trade Name Aerosil200] were added. The results are shown in Table 2.

Comparative Example 1

[0362] The procedure of Example 1 was repeated except thatethylene/propylene/5-ethylidene-2-norbornene random copolymer rubber(A-4) [Trade Name Mitsui EPT X-4010, manufactured by Mitsui ChemicalsInc.] was used in place of ethylene/propylene/5-vinyl-2-norbornenerandom copolymer rubber (A-1). The results are shown in Table 2.

Comparative Example 2

[0363] The procedure of Example 1 was repeated except thatethylene/propylene/dicyclopentadiene copolymer rubber (A-5) [Trade NameMitsui EPT X-3012P, manufactured by Mitsui Chemicals Inc.] was used inplace of ethylene/propylene/5-vinyl-2-norbornene random copolymer rubber(A-1). The results are shown in Table 2.

Comparative Example 3

[0364] The procedure of Example 1 was repeated except that polyisoprenecopolymer rubber (A-6) prepared in the following manner was used inplace of ethylene/propylene/5-vinyl-2-norbornene random copolymer rubber(A-1). The results are shown in Table 2.

[0365] Preparation of Polyisoprene copolymer rubber (A-6)

[0366] To a reaction vessel charged with 300 g of a hydrogenatedpolyisoprene having hydrosilyl groups at both ends [IdemitsuPetrochemicals Co. Ltd., Trade Mark: Epol], 50 ml of toluene was added,and dehydrated with azeotropic deaeration, and thereafter a solutionprepared by dissolving 48 g of t-BuOK in 200 ml of THF was injected.

[0367] The hydrogenated polyisoprene and t-BuOK were reacted at 50° C.for 1 hr, and 47 ml of allyl chloride was added dropwise to the reactionliquid over about 30 min. After the completion of the dropwise addition,30 g of aluminum silicate was added to the reaction liquid in order toabsorb the salt produced, and stirred at room temperature for 30 min.

[0368] Then, the mixture was purified with filtration to dim, prepareabout 250 g of hydrogenated polyisoprene having terminal allyl groups.The iodine value thereof determined by the iodine titration method was0.1 mol/100 g.

Comparative Example 4

[0369] The procedure of Example 2 was repeated except that 2.7 parts byweight of 100% dicumyl peroxide was used in place of 4.3 parts by weightof C₆H₅Si(—OSiMe₂H)₃ (B) (manufactured by Shinetsu Chemical IndustriesCo.) and 0.3 part by weight of 2% isopropyl alcohol solution ofchloroplatinic acid (C). The results are shown in Table 2.

Comparative Example 5

[0370] The procedure of Example 2 was repeated except that 1.5 parts byweight of sulfur (vulcanizer), 0.5 part by weight of2-mercaptobenzothiazole [manufactured by Sanshin Chemical Industries Co.Ltd., Trade Name Sanceler M], 1.0 part by weight of tetramethylthiuramdisulfide [manufactured by Sanshin Chemical Industries Co. Ltd., TradeName Sanceler TT], 5 parts by weight of zinc white and 1 part by weightof a stearic acid were used in place of 4.3 parts by weight ofC₆H₅Si(—OSiMe₂H)₃ (B) (manufactured by Shinetsu Chemical Industries Co.)and 0.3 part by weight of 2% isopropyl alcohol solution ofchloroplatinic acid (C). The results are shown in Table 2. TABLE 2-1Example 1 2 3 4 5 Composition [parts by weight] Copolymer rubber (A-1)100 Copolymer rubber (A-2) 100 100 Copolymer rubber (A-3) 100 100Copolymer rubber (A-4) Copolymer rubber (A-5) Copolymer rubber (A-6)C₆H₅Si(—OSiMe₂H)₃ (B) 4.3 4.3 4.3 4.3 4.3 2% IPA solution of 0.3 0.3 0.30.3 0.3 chloroplatinic acid (C) Ethynyl cyclohexanol (D) 0.01 0.013-GPTMS (E) 5 5 PW-32 (F) 120 300 120 400 Dicumyl peroxide SulfurSanceler-M Sanceler-TT Zinc white Stearic acid Aerosil 200 50Crosslinking rate (t_(c)(90)) [min] 15 21 29 39 52 Ozone resistance NoNo No No No cracking cracking cracking cracking cracking T_(B) [MPa ]0.3 0.4 0.4 0.4 0.8 E_(B) [%] 60 250 380 300 240

[0371] TABLE 2-2 Comparative Example 1 2 3 4 5 Composition [part byweight] Copolymer rubber (A-1) Copolymer rubber (A-2) 100 100 Copolymerrubber (A-3) Copolymer rubber (A-4) 100 Copolymer rubber (A-5) 100Copolymer rubber (A-6) 100 C₆H₅Si(—OSiMe₂H)₃ (B) 4.3 4.3 4.3 2% IPAsolution of 0.3 0.3 0.3 chloroplatinic acid (C) Ethynyl cyclohexanol (D)3-GPTMS (E) PW-32 (F) 120 120 Dicumyl peroxide 3.5 Sulfur 1.5 Sanceler-M0.5 Sanceler-TT 1 Zinc white 5 Stearic acid 1 Aerosil 200 Crosslinkingrate (t_(c)(90)) [min] 1000< 1000< 105 1000< 1000< Ozone resistance Lackof Lack of A-2 Lack of Lack of cross- cross- cross- cross- linkinglinking linking linking T_(B) [MPa] 0.4 0.1> 0.1> E_(B) [%] 120 1200 900

[0372] TABLE 3 Gelation time at room temperature (hrs) Example 1 15 2 213 29 4 39 5 52 Comparative Ex. 1 1000<  2 1000<  3 105  4 1000<  51000< 

1. A crosslinkable rubber composition, which is crosslinkable at roomtemperature, has a gelation time at room temperature of 30 days or less,and has the following properties: a crosslinked rubber sheet obtained bycrosslinking the composition at room temperature has a tensileelongation, as measured at a measuring temperature of 20° C. at atensile rate of 500 mm/min according to JIS K-6251, of 20% or more, andhas no crack on the sheet after a treatment at 40° C. in a 50 pphm ozoneconcentration for 96 hr in accordance with the ozone deterioration testmethod defined in JIS K-5259.
 2. A crosslinkable rubber compositioncomprising: (A) an ethylene/α-olefin/non-conjugated polyene randomcopolymer rubber (A) having structural units derived from at least onenorbornene compound having a vinyl group at the end, which compound isnon-conjugated polyene, represented by the following formula [I] or[II],

 wherein n is an integer of 0 to 10, R¹ is hydrogen or an alkyl group of1 to 10 carbon atoms, and R²is hydrogen or an alkyl group of 1 to 5carbon atoms,

 wherein R³ is hydrogen or an alkyl group of 1 to 10 carbon atoms, and(B) an SiH group-containing compound having at least two SiH groups inone molecule; and said composition having a gelation time at roomtemperature of 30 days or less.
 3. The crosslinkable rubber compositionaccording to claim 1 or 2, which has an adhesion strength to aluminum asdetermined by JIS A5758 (1986)of from 0.1 to 20 MPa.
 4. Thecrosslinkable rubber composition according to any one of claims 1 to 3,wherein the ethylene/α-olefin/non-conjugated polyene random copolymerrubber (A) has an intrinsic viscosity [η] as measured in decalin at 135°C. of from 0.01 to 0.95 dl/g.
 5. A crosslinkable rubber compositioncomprising (A) an ethylene/α-olefin/non-conjugated polyene randomcopolymer rubber (A) having structural units derived from at least onenorbornene compound having a vinyl group at the end, which compound isnon-conjugated polyene, represented by the following formula [I] or[II];

 in which n is an integer of 0 to 10, R¹ is hydrogen or an alkyl groupof 1 to 10 carbon atoms, and R² is hydrogen or an alkyl group of 1 to 5carbon atoms,

 in which R³ is hydrogen or an alkyl group of 1 to 10 carbon atoms, and(B) an SiH group-containing compound having at least two SiH groups inone molecule; and said composition having an adhesion strength toaluminum as determined by JIS A 5758(1986) of from 0.1 to 20 MPa.
 6. Acrosslinkable rubber composition comprising: (A) anethylene/α-olefin/non-conjugated polyene random copolymer rubber havingstructural units derived from at least one norbornene compound having avinyl group at the end, which compound is non-conjugated polyene,represented by the following formula [I] or [II];

 wherein n is an integer of 0 to 10, R¹ is hydrogen or an alkyl group of1 to 10 carbon atoms, and R² is hydrogen or an alkyl group of 1 to 5carbon atoms,

 wherein R³ is hydrogen or an alkyl group of 1 to 10 carbon atoms, and(B) an SiH group-containing compound having at least two SiH groups inone molecule, wherein the copolymer rubber (A) has an intrinsicviscosity [η] as measured in decalin at 135° C. of from 0.01 to 0.95dl/g.
 7. A crosslinkable rubber composition comprising: (A) anethylene/α-olefin/non-conjugated polyene random copolymer rubber havingstructural units derived from at least one norbornene compound having avinyl group at the end, which compound is non-conjugated polyene,represented by the following formula [I] or [II];

 wherein n is an integer of 0 to 10, R¹ is hydrogen or an alkyl group of1 to 10 carbon atoms, and R² is hydrogen or an alkyl group of 1 to 5carbon atoms,

 wherein R³ is hydrogen or an alkyl group of 1 to 10 carbon atoms, and(B) an SiH group-containing compound having at least two SiH groups inone molecule, wherein the composition has an adhesion strength toaluminum as determined by JIS A 5758(1986) of from 0.1 to 20 MPa, andthe copolymer rubber (A) has an intrinsic viscosity [η] as measured indecalin at 135° C. of 0.01 to 0.95 dl/g.
 8. The crosslinkable rubbercomposition according to any one of claims 2 to 7, which comprises: (A)an ethylene/α-olefin/non-conjugated polyene random copolymer rubber, (B)an SiH group-containing compound which has at least two SiH groups inone molecule, (C) a catalyst and (D) a reaction inhibitor or (E) asilane coupling agent.
 9. The crosslinkable rubber composition accordingto any one of claims 2 to 7, which has the properties as claimed inclaim
 1. 10. The crosslinkable rubber composition according to any oneof claims 1 to 7, which is used for electric and electronic parts,transportation machines, civil engineering and construction materials,medical appliances and goods for leisure activities.
 11. Thecrosslinkable rubber composition according to claim 10, wherein the usesfor the electric and electronic parts include sealing materials, pottingmaterials, coating materials or adhesives, applied to heavy electricapparatus parts, light electrical appliance parts, or circuits andsubstrates of electric and electronic machinery and tools; repairingmaterials for covered electric cable; insulating sealing materials forelectric cable joint parts; rolls for office automation equipments;vibration absorbing materials; and gels or encapsulation materials forcondensers.
 12. The crosslinkable rubber composition according to claim11, wherein the sealing materials are used for refrigerators, freezers,washing machines, gas meters, microwave ovens, steam irons and circuitbreakers.
 13. The crosslinkable rubber composition according to claim11, wherein the potting materials are used for potting transformerhigh-tension circuits, printed boards, high voltage transformersequipped with a variable resistor, electrical insulating parts,semi-conductive parts, conductive parts, solar cells and TV fly-backtransformers.
 14. The crosslinkable rubber composition according toclaim 11, wherein the coating materials are used for coating circuitelements of a high voltage thick film-resistor and a hybrid IC; HIC;electrical insulating parts; semi-conductive parts, conductive parts;modules; printed circuits; ceramic boards; buffer materials for diodes,transistors or bonding wires; semi-conductive elements; and opticalfibers for optical communication.
 15. The crosslinkable rubbercomposition according to claim 11, wherein the adhesives are used forbonding cathode-ray tube wedges or necks, electrical insulating parts,semi-conductive parts and conductive parts.
 16. The crosslinkable rubbercomposition according to claim 10, wherein the uses for thetransportation machines include automobiles, ships, airplanes andrailway vehicles.
 17. The crosslinkable rubber composition according toclaim 16, wherein the uses for automobiles include sealing materials forgaskets of automobile engines, electric trim parts or oil filters;potting materials for igniter HIC and automobile hybrid IC; coatingmaterials for automobile bodies, automobile window glass and enginecontrol substrates; and adhesives for gasket of oil pans, gaskets oftiming belt covers, automotive moles, head lamp lenses, sun roof sealsor mirrors.
 18. The crosslinkable rubber composition according to claim16, wherein the uses for ships include sealing materials for wiring andconnecting distributor boxes, electric system parts and electric wires;and adhesives for electric wires or glass.
 19. The crosslinkable rubbercomposition according to claim 10, wherein the uses for civilengineering and construction include sealants of building materials forbutt joints in glass screen method of commercial buildings, joints ofglass fringes fixed with sash, interior finishing joints of toiletfacilities, lavatory or show cases, joints of bath tub circumferences,outer wall expansion joints of prefabrication houses and joints ofsiding boards; sealing materials for double glazing units; civilengineering sealants used in road maintenance; coatings and adhesivesused for metals, glass, stone materials, slates, concretes and tiles;and adhesive sheets, water proofing sheets and vibration-proof sheets.20. The crosslinkable rubber composition according to claim 10, whereinthe uses for medical appliances include sealing materials for medicalrubber stoppers, syringe gaskets and rubber stoppers for reducing bloodpressure.
 21. The crosslinkable rubber composition according to claim10, wherein the uses for leisure activity goods include swimmingmaterials for swimming caps, diving masks or earplugs; and gel buffermaterials for sport shoes or baseball gloves.
 22. A sealing materialcomprising the crosslinkable rubber composition as claimed in any one ofclaims 1 to
 9. 23. A potting material comprising the crosslinkablerubber composition as claimed in any one of claims 1 to
 9. 24. A coatingmaterial comprising the crosslinkable rubber composition as claimed inany one of claims 1 to
 9. 25. An adhesive comprising the crosslinkablerubber composition as claimed in any one of claims 1 to 9.